Question

The reaction between copper oxide and nitric acid forms:
A. copper nitrate and hydrogen
B. copper nitrite and water
C. copper nitrite and hydrogen
D. copper nitrate and water

Answer 1

As we know the chemical formula of copper oxide and nitric acid is ${\text{CuO}}$ and ${\text{HN}}{{\text{O}}_{\text{3}}}$ respectively. Moreover, when nitric acid reacts with copper at two different temperatures then there will be two different types of products formed.

Complete step by step answer: Firstly, copper oxide is a compound formed by two elements copper and oxygen. Copper is a reddish-brown metal. Talking about nitric acid, it is a strong acid with the formula ${\text{HN}}{{\text{O}}_{\text{3}}}$. Moreover, in its pure form, it is colourless but when it gets older it turns into a yellow cast. The reaction between copper oxide and nitric acid is an example of oxidation-reduction reactions, in which gaining of electrons reduces the one element and the latter, while losing them oxidizes the other. So, the reaction that occurs is a redox reaction. Nitric acid is an extremely corrosive acid and is capable of causing severe burns. If it gets in contact with eyes, it can cause permanent cornea damage. So, we have to handle this acid very carefully. It is well known that copper is the only one which reacts with nitric acid. So, according to the question, when copper oxide reacts with nitric acid, it gives copper nitrate and water. The equation is given as below:
${\text{CuO + 2HN}}{{\text{O}}_{\text{3}}} \to {\text{Cu(N}}{{\text{O}}_{\text{3}}}{{\text{)}}_{\text{2}}}{\text{ + }}{{\text{H}}_{\text{2}}}{\text{O}}$
To balance the equation, we apply ${\text{2}}$with nitric acid.
So, the option D) is correct i.e. copper nitrate and water.

Note: When copper oxide reacts with nitric acid, then no hydrogen gas is evolved because of the oxidizing nature of the nitric acid. When nitric acid reacts with any metal, it produces a salt with water and nitrogen dioxide gas.